JPH0465285A - No carbon copying paper - Google Patents

Abstract

PURPOSE:To prevent useless coloring stains and blur of printing or the like of a developed sheet surface and a colored sheet surface by a method wherein a ratio of solvent to color former which are used for an inner phase of a microcapsule is specified. CONSTITUTION:No-carbon copying paper is formed as follows. Electron acceptive developer of a color former layer having microcapsule buffer (e) with inner phase oil containing dissolved electron donative color former as core substance and adhesives (f) as principal components is a multivalent metal salt compound composed of salicylate resin multivalent metal compound of allowing multivalent metal salt to react with resin obtained by adding styrene derivative to salicylate derivative having aromatic substituent under presence of strong acid catalyst and/or salicylates, resin group, and multivalent metal compound. The inner phase oil, the core substance of the microcapsule, contains 4.5-8.0wt.% of Crystal Violet lactone. Volumetric mean grain size of the microcapsule containing Crystal Violet lactone as a part of the core substance is 3-8mum.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a color developing sheet for carbonless copying paper.

[Conventional technology]

Carbonless copying paper is known, for example, as described in U.S. Pat.
No. 5115470, No. 2730465, No. 25054
As described in No. 89, No. 2730457, etc., a colorless organic compound (hereinafter referred to as a color former) that has electron donating properties, adsorption properties, and coloring reactivity is dissolved in an organic solvent. This method utilizes a contact reaction between microcapsules and an electron-accepting, reactive, adsorbent substance (hereinafter referred to as a color developer). - When using carbonless copy paper on a boat, the coated side of the top paper coated with microcapsules containing a coloring agent is placed over the coated side of the bottom paper coated with a color developer and pressure is applied. The capsule is destroyed and a colored image is obtained. In this application, a color forming agent and a color developing agent are applied separately to the back and front sides of a single sheet, and the paper is inserted between the top paper and the bottom paper to make multiple copies. There are self-contained types in which a color former and a color developer are applied on the same side. Color developers include inorganic solid acids such as activated clay and acid clay, novolak-type phenol-formaldehyde resins, organic carboxylic acids and their metal salts, but it is difficult to erase colored characters with water or organic chemicals such as plasticizers. There were problems such as color and yellowing of the paint layer due to sunlight and NOx gas, and it was not completely satisfactory. However, recently, polyvalent metal salts made of salicylic acids, rosins, and polyvalent metal compounds (hereinafter referred to as color developer (A)) and aromatic substituted A salicylic acid resin polyvalent metal compound (such as JP-A-63-186729, etc.), which is obtained by reacting a polyvalent metal salt with a resin obtained by adding a styrene derivative to a salicylic acid derivative having a group, is hereinafter referred to as a color developer ( B) has been disclosed and the above-mentioned problems have been improved. What these color developers have in common is that they are similar to the solvents used in the internal phase of microcapsules, such as oils and solvents.
The reason is that rosins and styrene derivatives, which are easily compatible, are introduced. As a result, the color development speed immediately after pressurized printing is excellent, and a darkly colored image can be obtained instantly, which is an advantage not seen in the past. However, contrary to this, a drawback has also appeared, which appears to be due to too high compatibility with the internal phase solvent. That is, for example, colored stains and inner paper caused by presser foot pressure during guillotine cutting when setting top paper - bottom paper, soil paper - middle paper - bottom paper, pressure when stacking, friction during transportation, etc. When handling the product, unintended color stains are likely to occur due to misalignment of the roll in the coater, wine goo, printing machine, etc. This colored stain may be transferred not only to the color developing sheet surface but also to the opposing color developing sheet surface. The surface of the color-developing sheet is sometimes subjected to printing in the same way as the surface of the color-developing sheet, and is very unsightly. In addition, it has become clear that printed characters tend to bleed, making them extremely difficult to read, especially when many copies of Chinese characters with a large number of strokes are made. The following methods can be used to improve such colored stains and bleeding of printed characters. 0 The pigment used in the color developing sheet should have low oil absorption. 0 Provide a protective layer on the color developing sheet or coloring sheet. 0 Decrease the ratio of color developer used in the color developer sheet. 0 Reduce the amount of microcapsules applied on the coloring sheet. 0 Increase the viscosity of the solvent used in the microcapsules of the color-forming sheet. 0 Increase the usage ratio of buffering agent used in the color development sheet. O Make the microcapsules used in the coloring sheet small in size. 0 Increase the film thickness of the microcapsules used in the color-developing sheet. 0 Increase the amount of adhesive used for the color-developing sheet and color-developing sheet more than necessary. It has been found that if these methods are followed, unnecessary color development stains and print bleeding can be improved to some extent, but all methods cannot be improved without sacrificing the necessary color development performance.

[Problem to be solved by the invention]

That is, an object of the present invention is to provide a carbonless copying paper in which unnecessary coloring stains and bleeding of printed characters on the coloring sheet surface and the coloring sheet surface are improved without sacrificing necessary coloring performance. .

[Means to solve the problem]

In the present invention, we use a color developer that is highly compatible with the solvent in the capsule internal phase to improve unnecessary color development stains and bleeding such as printing without sacrificing the necessary color development performance. As a result of various studies focusing on the ratio of the solvent and coloring agent used in the internal phase of the capsule, it was fortunately discovered for the first time that effects far superior to those of the various improvement methods described above can be obtained, and the present invention has been made. It's arrived. The solvent used for the internal phase of the microcapsules is not particularly limited, and those commonly used in the art can be used. Examples include diarylalkane, alkylnaphthalene, dibedylbenzene derivatives, alkylbenzene, paraffin, cycloparaffin, chlorinated paraffin, various esters, mineral oils, vegetable oils, and the like. As the color former, crystal violet lactone (CVt) is most preferable from the viewpoint of sharpness of hue, color density of image, solubility in solvent, etc., and a small amount of other color formers are used in combination to adjust the color to the desired hue. You may. For example, (1) 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(p-
dimethylaminophenyl)-3-(1゜2-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-methylindole-3-
yl)phthalide, 3(p-dimethylaminophenyl)-
3-(2-phenylindol-3-yl)phthalide,
3,3-bis-(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-bis-(
1,2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3-bis-(9-ethylcarbazol-3-yl)-5-dimethylaminophthalide, 3
,3-bis-(2-phenylindol-3-yl)-
5-dimethylaminophthalide, 3-p-dimethylaminophenyl-3-(1-methylpyrrol-2-yl)-6
-Simethyl-aminophthalide, etc.: (2) As a diphenylmethane compound, 4. 4'-
Bis-dimethylaminobenzhydrin benzyl ether, N-halophenylleucoolamine, N-2,4,5
-) Lichlorophenylleucoolamine, etc.: (3) As xanthine compounds, rhodamine B-anilinolactam, rhodamine B-p-nitroanilinolactam, rhodamine B-p-chloroanilinolactam, 3
-diethylamino-7-dibenzylaminofluorane,
3-diethylamino-7-octylaminofluorane,
3-diethylamino-7-phenylfluorane, 3-diethylamino-7-3,4-dichloroanilinofluorane, 3-diethylamino-7-(2-chloroanilino)
Fluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-
Anilinofluorane, 3-ethyl-tolylamino-6-
Methyl-7-anilinofluorane, 3-ethyl-tolylamino-6-methyl=7-phenylfluorane, 3-diethylamino-7-(4-nitroanilino)fluorane, etc. = (4) As a thiazine compound, benzoylleucomethylene blue , p-nitrobenzoylleucomethylene blue, etc.: (5) As spiro compounds, 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran,
3.3'-Cyclolosespirodinaphthopyran, 3
-Benzylspiro-dinaphthopyran, 3-methylnaphthol-(3-methoxy-benzo)spiropyran, etc.: Others, Special Publication No. 51-161107 No. 1, Special Publication No. 5B-
No. 20798, Special Publication No. 5B-21824, Special Publication No. 5g
-29239, Unexamined Patent Publication! -95161, JP-A-1-
Indolyl (aza) described in various publications such as No. 216993
As a result of many tests involving color formers such as phthalides, the ratio of the internal phase solvent of microcapsules to crystal violet lactone was 95% on a weight basis.
．． 5:4.5-92:81, even 95:5-92:
It was found for the first time that a region with an unusually high ratio of crystal violet lactone, ie, 8, is preferable. If the ratio of crystal violet lactone is lower than this, the necessary coloring density can be obtained, but unnecessary coloring stains and bleeding such as printing cannot be improved. In addition, if the ratio of crystal violet lactone is increased, color development stains and bleeding of printing can be further improved, but the necessary color development density cannot be obtained (in particular, the color development speed immediately after printing is insufficient). Now, let's look at the examples of specifications disclosed in the past to find out what percentage of the coloring agent (crystal violet lactone) in carbonless copying paper is contained in the internal composition of JP-A-59. -2.8%60-19 in Publication No. 48184
0228 5.7% 60-216838 1.9% 61-438 4.4% 61-11138 2.9% 61-15734 3.4% 61-21728 3.5% 61-118133 4.8% 61-174941 3.8% 62-105686 4.8% 62-129141 3.8% 62-178386 1% 62-193641 4.8%62-213
838 4.3%62-269742
3.5%62-277146 3. 8%
JP-A-1-288480 is 3.8%, and the overwhelming majority are in the 3-4% range. Although there are examples in which the concentration of the color former is 4.5% or more, the type of color developer used in combination is inappropriate, and high-performance carbonless copying paper cannot be obtained. Good carbonless copying paper was only obtained when the specific color developer used in the present invention was used and the crystal violet concentration was unusually high. The method of microencapsulation is not particularly limited, and conventionally known methods can be used. Typical methods include, for example: Coacervation method using gelatin-gum arabic ionic complex Interfacial polymerization method in which an insoluble film is formed at the interface between a hydrophilic liquid as a dispersion medium and a hydrophobic liquid to be included. After adding a coating resin initial condensate such as melamine-formalin resin or urea-formalin resin from the side of the hydrophilic liquid serving as a dispersion medium, it is converted into a resin and encapsulated.
gHa polymerization method (JP 53-84881, JP 54-25
277, 54-499114, 55-41139,
56-51238, 59-177129>, etc. The particle size of microcapsules is 3 μm to 8 μm on average by volume.
is preferable, and more preferably 4 μm to 7 μm. If it is smaller than this range, colored stains can be further improved, but it becomes difficult to obtain sufficient coloring performance, and if it is larger than this range, it will be easily destroyed by friction, and colored stains may not be completely prevented. Buffers are added for the purpose of preventing destruction of microcapsules, and generally wheat starch, potato starch, fine cellulose powder, synthetic plastic pigments, etc. are used, and are usually added in amounts per 100 parts by weight of microcapsules. , used in a range of 10 to 100 parts. As the adhesive, conventionally known adhesives can be used. For example, proteins such as casein and gelatin, cellulose derivatives such as carboxymethylcellulose and hydroxymethylcellulose, water-soluble natural polymer compounds such as sucrose such as oxidized starch and esterified starch, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, and styrene-butylene. Water-soluble synthetic polymer compounds and latexes such as Gen latex, acrylonitrile-butadiene-acrylic acid latex, polyacrylamide, styrene-maleic anhydride copolymer, etc. can be used. On the other hand, the color developer used in the color developer sheet is the aforementioned color developer (A
) or developer (B), but if necessary, (A) and (
B) can also be used in combination. The method for producing the color developer (B) includes salicylic acid and α. Polyvalent metal compounds of co-condensed resins such as α゛-dialkoxy-p-xylene (JP-A-62-176875, JP-A No. 62-178387, JP-A No. 62-1783118, JP-A No. 63-53092, JP-A No. 63-159082, 63-
160877) A polyvalent metallized resin obtained by reacting a styrene derivative with a salicylic acid derivative having an aromatic substituent (Japanese Unexamined Patent Publication No. 186729), a salicylic acid derivative having an aromatic substituent with benzyl halides Polyvalent metal compound of resin obtained by reacting
3-254124), and other Japanese Patent Laid-Open No. 63-289
There are resin polyvalent metal compounds described in No. 017. Examples of salicylic acids and salicylic acid derivatives used in the color developer (^) or color developer (B) include salicylic acid, 5-tcrt-butylsalicylic acid, 3゜5-diI
ef+-butylsalicylic acid, 3,5-di-1eit-aminosalicylic acid, 3,5-di@ec-butylsalicylic acid, 5-nonylsalicylic acid, 3-methyl-5-isoamylsalicylic acid, 5-isoamylsalicylic acid, 3-cyclohexyl salicylic acid, 5-cyclohexylsalicylic acid,
3,5-dicyclohexylsalicylic acid, 3,5-di(α
, α-dimethylbenzyl)salicylic acid, 3.5-dibenzylsalicylic acid, 3-(α,α-dimethylbenzyl)-
5-1erj-butylsalicylic acid, 3.5-di(α-methylbenzyl)salicylic acid, 3-phenylsalicylic acid,
3,5-diphenylsalicylic acid, 3-phenyl-5-I
Part e - Butylsalicylic acid, 3-benzyl-5-phenylsalicylic acid, 3.5-dichlorosalicylic acid, 3-chloro-5-methylsalicylic acid, 3-chloro-5-ethylsalicylic acid, 3-chloro-5-phenylsalicylic acid, Examples include salicylic acid formaldehyde polymer, 2,6-dihydroxybenzoic acid-formaldehyde polymer, and the like. The adhesive used for the color-developing sheet can be the same as that for the color-developing sheet, and the pigment can be either organic or inorganic, such as polystyrene, polyvinyltoluene, styrene-divinylbenzene copolymer, Polymethyl methacrylate, urea-formaldehyde polymer, calcium carbonate, talc, clay, kaolin, calcined kaolin, barium sulfate, barium carbonate, magnesium carbonate, silica powder, magnesium silicate, lead sulfate, white lead, zinc white, zinc sulfide , satin white, titanium oxide, antimony oxide, bentonite, mica, calcium silicate, gypsum, acid clay, activated clay, zeolite, aluminum hydroxide, and the like. In addition, antifoaming agents, dispersants, lubricants, penetrants, waterproofing agents, and the like can be used as necessary. Further, the method of applying the carbonless copying paper of the present invention is not particularly limited, and a method using a coater head such as an F-knife, a roll, a blade, a rod, a curtain, a size press, etc. can be used. (Function) It has been found for the first time that the present invention can improve the bleeding of printed characters, color developer sheets, and unnecessary color development stains on the coated surface of color development sheets without sacrificing color development performance. The reason is considered to be that the solvent encapsulated in the microcapsules of the coloring sheet decreased and the coloring agent increased relatively abnormally. (Example) The present invention will be explained in more detail with reference to Examples, but of course the present invention is not limited to the Examples. In the examples, "parts" and "%" are all "parts by weight" and "% by weight".
” refers to Example 1 A microcapsule paint containing a color former was prepared as follows. Crystal violet lactone (CVL) 4°5g Hysol SAS N-296 (Japan Petrochemical System) 9
5.5 g was heated and dissolved to obtain an internal phase oil. This internal phase oil was emulsified in a 4% styrene maleic anhydride copolymer aqueous solution, and 10 g of melamine and 25 g of 37% formalin were added.
and was heated at pH 8 to obtain a melamine-formalin initial polycondensate. This was added to the above emulsion while stirring, and the pH of the system was maintained at 5.6, and the liquid temperature was maintained at 70° C. for 2 hours to obtain a capsule dispersion containing a coloring agent and having a melamine-formalin resin film. The volume average particle size was 3.2 microns. 30 parts of wheat starch particles and 100 parts of a 10% polyvinyl alcohol aqueous solution were added to 1.0 parts of the solid microcapsule liquid obtained in this way, and the mixture was coated on 40 g and 10 f of high-quality paper so that the CVL coating amount was 80 μ/d. A coloring sheet for carbon copying paper was obtained. A color developer and a paint containing the color developer were prepared as follows. In a 500 ml flask equipped with a stirrer, thermometer and condenser were added 80.1 g (0.58 mol) of salicylic acid and 84.2 g (0.58 mol) of gum rosin (acid value 168 KOtl/g).
25 mol), zinc oxide 34. 2g (0.42 mol)
, ammonium bicarbonate 17.1 g, 2-butanone 164
．． 3 g was charged and refluxed at 80° C. for 1 hour. Thereafter, unreacted inorganic substances were removed by filtration, and the solvent was distilled off to obtain 187 g of a zinc salt compound (Japanese Patent Application Laid-Open No.
(color developer based on Publication No. 563). A color developer paint was prepared using 15 parts by dry weight of this color developer, 100 parts of kaolin, and 15 parts of oxidized starch. Then, it was coated on 40 glrd high-quality paper at a dry coating amount of 6 g/po to obtain a color developing sheet for carbonless copying paper. Example 2 The color developer used in the color developer sheet in Example 1 was replaced with the color developer (B
) A color-developing sheet and a color-developing sheet for carbonless copying paper were obtained in the same manner as in Example 1, except that the color-developing sheet and the color-developing sheet for carbonless copying paper were prepared. Color developer (B) is 3,5-di(4-methylbenzyl)salicylic acid6. This is a zinc salt of a resin obtained by reacting 9 g (0.02 mol) of styrene with 6.24 g (0.06 mol) of styrene using sulfuric acid as a catalyst (a color developer based on JP-A-63-186729). Example 3 In Example 1, the volume average particle diameter of the microcapsules was 7.
．． A color developing sheet and a color developing sheet were obtained in the same manner as in Example 1 except that the thickness was 8 μm. Example 4 The color developing sheet of Example 3 and the color developing sheet of Example 2 were combined and evaluated. Example 5 Color-developing sheet and developer sheet for carbonless copying paper similar to Example 1 except that the color-developing sheet was prepared using 92 parts of Hysol SAS, N-296 and 8 parts of Crystal Violet Lactone. I got it. Example 6 The color-developing sheet was evaluated in combination with that of Example 5, and the color-developing sheet was combined with that of Example 2. Example 7 The volume average particle diameter of the microcapsules in Example 5 was 7.
．． A color-developing sheet and a color-developing sheet for carbonless copying paper were obtained in the same manner as in Example 5 except that the thickness was 8 μm. Example 8 The color developing sheet of Example 7 and the color developing sheet of Example 2 were combined and evaluated. Example 9 Same as Example 1 except that Hysol SAS, N-296 was 94 parts, Crystal Violet Lactone was 6 parts, and the volume average particle diameter of the microcapsules was 6 μm.For carbonless copying paper. A color developing sheet and a color developing sheet were obtained. Example 10 The color developing sheet of Example 9 and the color developing sheet of Example 2 were combined and evaluated. Example 11 The color developer used in the color developer sheet of Example 9 was the color developer (^
) and color developer (8) were used in combination at a ratio of 1:1 to obtain a color-developing sheet and a color-developing sheet for carbonless copying paper in the same manner as in Example 9, except that they were used together in a ratio of 1:1. Example 12 Carbonless copying paper (inner paper) was obtained by applying the paint containing a color former and the paint containing a color developer in Example 9 to different sides of a 40 g/rrf high-quality paper. Comparative Example 1 Hysol 5ASSN-296 of Example 1 was 95.
A color-developing sheet and a color-developing sheet for carbonless copying paper were obtained in the same manner as in Example 1 except that 8 parts of crystal violet lactone and 4.2 parts of crystal violet lactone were used, and the volume average particle diameter of the microcapsules was 2.7 μm. Comparative Example 2 The color developing sheet of Comparative Example 1 and the color developing sheet of Example 2 were combined and evaluated. Comparative Example 3 A color-developing sheet and a color-developing sheet for carbonless copying paper were obtained in the same manner as in Example 1 except that the volume average particle diameter of the microcapsules was 8.5 μm. Comparative Example 4 Of Example 1, Hysol SAS, N-296 was 91.
A color-developing sheet and a color-developing sheet for carbonless copying paper were obtained in the same manner as in Example 1, except that the volume average particle size of the microcapsules was 8.5 μm. Comparative Example 5 The volume average particle diameter of the microcapsules of Example 4 was 2.8.
A color-developing sheet and a color-developing sheet for carbonless copying paper were obtained in the same manner as Comparative Example 4, except that the thickness was set to .mu.m. The carbonless copying papers obtained in the above Examples and Comparative Examples were evaluated as follows. 0 color density Overlap so that the color former and color developer coated surfaces face each other,
The sample was passed through a calendar at a pressure of 96 kg/car, and after 1 minute and 24 hours, the value was determined using a color difference meter NDIOIDP model manufactured by Nippon Heavy Industries, Ltd. according to the following formula. The smaller the value, the darker the color density. 0 Unnecessary Colored Stains A pressure of 30 kg/car was applied for 10 minutes, and 24 hours later, the colored stains were measured in the same manner as the color density. With this test, it is possible to determine the color stains caused by the pressure of the guillotine's presser foot and the weight of the objects when they are stacked. The higher the value, the less likely it is to get dirty. Bleeding of 0 characters was printed using a typewriter, and the degree of bleeding was visually determined. ○・・・It's hardly a carrot △・・・It's a little blurred ×・・・It's a big blur (the following is the margin)

【Effect of the invention】

As is clear from the above, the carbonless copying paper of the present invention has improved unnecessary coloring stains and bleeding of printing on the coloring sheet surface and coloring sheet surface without sacrificing the necessary coloring performance. The performance was excellent. Procedural amendment (acid) September 14, 1990 1, Indication of the case 2, Title of the invention 1990 Patent Application No. 178697 Carbonless Copy Paper 3, Person making the amendment Relationship with the case

Claims (1)

[Claims] 1. Basically (a) an electron-accepting color developer, (b) an adhesive,
and (c) a color developer layer containing a pigment as a main component; (d) a microcapsule whose core substance is an internal phase oil containing a dissolved electron-donating coloring agent; (e) a buffer; and (f) an adhesive. A carbonless copying paper in which a color forming agent layer containing a coloring agent as a main component is applied separately to one side of different supports or both sides of the same support and dried, and the thus obtained color developing agent layer and color forming agent layer are used in combination. (a) The electron-accepting color developer is a salicylic acid resin polyurethane obtained by reacting a polyvalent metal salt with a resin obtained by adding a styrene derivative to a salicylic acid derivative having an aromatic substituent in the presence of a strong acid catalyst. The inner phase oil, which is a polyvalent metal salt compound consisting of a valent metal compound and/or salicylic acids, rosin, and a polyvalent metal compound, and which is the core material of the microcapsule (d) has a weight of 4.5 to 50% on a weight basis. A carbonless copying paper characterized by containing 8.0% crystal violet lactone. 2. The volume average particle diameter of the microcapsules containing crystal violet lactone as part of the core substance is 3 to 8 μm.
The carbonless copying paper according to claim 1, wherein the carbonless copying paper is m.